1. Field of the Invention
The present invention relates to a recording apparatus and an image processing method.
2. Description of the Related Art
Inkjet printing apparatuses record an image by discharging a plurality of ink droplets that form the image from an inkjet head onto a recording medium. Each of the plurality of ink droplets is expected to be discharged according to a predetermined desired discharge amount. In some cases, due to various kinds of errors included in the printing apparatus, such as an error when the ink or the head is manufactured, the volume of an ink droplet discharged from the print head may be different from the original desired amount, affecting the density of a recorded product. Therefore, recording a test pattern by the printing apparatus, detecting the recorded density by a sensor including a light emitting portion and a light receiving portion, and correcting image data in such a manner that a recorded image has a desired density have been conducted. However, there is a variation in the optical characteristics of the light emitting portion and the light receiving portion among sensors. A reading result of the sensor affects the density of a recorded product in this correction, so that it is important to secure the reading accuracy of the sensor in advance.
Japanese Patent Application Laid-Open No. 9-171279 discusses a method for calibration of a reading sensor. According to this method, a reference chart is read, and correction data is generated based on a difference from a target to correct a variation in a spectral characteristic of a color filter of a color scanner.
However, according to the method using the reference chart, the chart is required every time the correction is performed. Further, this method has a problem of its lack of simpleness, since a variation in the chart and a change due to aging should be taken into consideration.